Amplifiers are used in many areas of electronics to increase amplitudes of various signals in ways needed by a circuit. For example, audio electronics employ amplifiers to drive speakers at higher volumes by amplifying an audio input signal. Amplifiers are classified in a number of different classifications, one of which is class D. Class D amplifiers (sometimes called switching amplifiers) generate a variable-duty-cycle square wave representing the desired digital output signal (e.g., an audio output signal to drive a speaker) by digitally integrating a feedback signal in the amplification feedback loop. The switching frequency is typically chosen to be ten or more times the highest frequency of interest in the input signal.
In this manner, a class D amplifier delivers a constantly changing voltage signal to a fixed load (e.g., speaker) as modulated by the integrated feedback signal. However, if the digital integrator becomes saturated due to a high level input signal or an out of control feedback loop, the output signal will become distorted in a manner commonly referred to as “clipping”. Output clipping is a problem that may cause the class D amplifier to introduce noise or other distortion into the output audio signal which is not desirable.